金属热处理 ›› 2021, Vol. 46 ›› Issue (7): 178-181.DOI: 10.13251/j.issn.0254-6051.2021.07.034

• 工艺研究 • 上一篇    下一篇

冷却工艺对贝氏体钢拉杆组织和性能的影响

李梦鸽, 程巨强, 尹思博   

  1. 西安工业大学 材料与化工学院, 陕西 西安 710021
  • 收稿日期:2021-03-09 出版日期:2021-07-25 发布日期:2021-12-10
  • 通讯作者: 程巨强(1963—),男,教授,主要研究方向为金属材料的组织和性能的研究与应用,E-mail:chengjuqiang@163.com
  • 作者简介:李梦鸽(1996—),女,硕士研究生,主要研究方向为高强度钢铁材料研究与应用,E-mail:2492074531@qq.com。

Effect of heat treatment and cooling process on microstructure and properties of bainitic steel tie-rods

Li Mengge, Cheng Juqiang, Yin Sibo   

  1. College of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an Shaanxi 710021, China
  • Received:2021-03-09 Online:2021-07-25 Published:2021-12-10

摘要: 研究了热处理冷却工艺对贝氏体钢拉杆组织及力学性能的影响。试验结果表明,ø70 mm贝氏体钢拉杆材料经920 ℃空冷+300 ℃回火、920 ℃水冷30 s后出水空冷+300 ℃回火后,杆体的组织为贝氏体铁素体和残留奥氏体;经920 ℃水冷+200 ℃回火后,杆体的组织为回火板条马氏体和残留奥氏体。920 ℃水冷+200 ℃回火时棒料1/2半径处的Rm为1513 MPa、KV2为73.2 J、硬度为46.5 HRC;920 ℃水冷30 s后空冷+300 ℃回火时棒料1/2半径处的Rm为1254 MPa、KV2为76.0 J、硬度为42.0 HRC;920 ℃空冷+300 ℃回火时棒料1/2半径处的Rm为1226 MPa、KV2为75.5 J、硬度为41.9 HRC。ø70 mm贝氏体钢拉杆热处理先水冷后空冷可以提高其冲击性能。

关键词: 冷却方式, 贝氏体钢拉杆, 组织, 性能

Abstract: The effects of heat treatment and cooling process on the microstructure and mechanical properties of the bainitic steel tie-rod with 70 mm in diameter were studied. The results show that the structure of the rod is bainite ferrite and residual austenite when heated at 920 ℃ and air cooled, and then tempered at 300 ℃, or heated at 920 ℃, water cooled for 30 s and air cooled, and then tempered at 300 ℃. The structure of the rod body is tempered lath martensite and retained austenite when heated at 920 ℃, water cooled and then tempered at 200 ℃. At half radius of the bar after water cooling at 920 ℃ and tempering at 200 ℃, Rm is 1513 MPa, KV2 is 73.2 J, hardness is 46.5 HRC; after water-cooling for 30 s and air cooling at 920 ℃ and tempering at 300 ℃, Rm is 1254 MPa, KV2 is 76.0 J, hardness is 42.0 HRC; after air cooling at 920 ℃ and tempering at 300 ℃, Rm is 1226 MPa, KV2 is 75.5 J and hardness is 41.9 HRC. When the ø70 mm bainitic steel tie rod is actually normalized, the impact toughness can be improved by water-cooling before air-cooling.

Key words: cooling mode, bainite steel rod, microstructure, property

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